Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / net / ipv6 / ip6_tunnel.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      IPv6 tunneling device
4  *      Linux INET6 implementation
5  *
6  *      Authors:
7  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
8  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
9  *
10  *      Based on:
11  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
12  *
13  *      RFC 2473
14  */
15
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18 #include <linux/module.h>
19 #include <linux/capability.h>
20 #include <linux/errno.h>
21 #include <linux/types.h>
22 #include <linux/sockios.h>
23 #include <linux/icmp.h>
24 #include <linux/if.h>
25 #include <linux/in.h>
26 #include <linux/ip.h>
27 #include <linux/net.h>
28 #include <linux/in6.h>
29 #include <linux/netdevice.h>
30 #include <linux/if_arp.h>
31 #include <linux/icmpv6.h>
32 #include <linux/init.h>
33 #include <linux/route.h>
34 #include <linux/rtnetlink.h>
35 #include <linux/netfilter_ipv6.h>
36 #include <linux/slab.h>
37 #include <linux/hash.h>
38 #include <linux/etherdevice.h>
39
40 #include <linux/uaccess.h>
41 #include <linux/atomic.h>
42
43 #include <net/icmp.h>
44 #include <net/ip.h>
45 #include <net/ip_tunnels.h>
46 #include <net/ipv6.h>
47 #include <net/ip6_route.h>
48 #include <net/addrconf.h>
49 #include <net/ip6_tunnel.h>
50 #include <net/xfrm.h>
51 #include <net/dsfield.h>
52 #include <net/inet_ecn.h>
53 #include <net/net_namespace.h>
54 #include <net/netns/generic.h>
55 #include <net/dst_metadata.h>
56
57 MODULE_AUTHOR("Ville Nuorvala");
58 MODULE_DESCRIPTION("IPv6 tunneling device");
59 MODULE_LICENSE("GPL");
60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
61 MODULE_ALIAS_NETDEV("ip6tnl0");
62
63 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
65
66 static bool log_ecn_error = true;
67 module_param(log_ecn_error, bool, 0644);
68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
69
70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
71 {
72         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
73
74         return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
75 }
76
77 static int ip6_tnl_dev_init(struct net_device *dev);
78 static void ip6_tnl_dev_setup(struct net_device *dev);
79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
80
81 static unsigned int ip6_tnl_net_id __read_mostly;
82 struct ip6_tnl_net {
83         /* the IPv6 tunnel fallback device */
84         struct net_device *fb_tnl_dev;
85         /* lists for storing tunnels in use */
86         struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
87         struct ip6_tnl __rcu *tnls_wc[1];
88         struct ip6_tnl __rcu **tnls[2];
89         struct ip6_tnl __rcu *collect_md_tun;
90 };
91
92 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
93 {
94         struct pcpu_sw_netstats tmp, sum = { 0 };
95         int i;
96
97         for_each_possible_cpu(i) {
98                 unsigned int start;
99                 const struct pcpu_sw_netstats *tstats =
100                                                    per_cpu_ptr(dev->tstats, i);
101
102                 do {
103                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
104                         tmp.rx_packets = tstats->rx_packets;
105                         tmp.rx_bytes = tstats->rx_bytes;
106                         tmp.tx_packets = tstats->tx_packets;
107                         tmp.tx_bytes =  tstats->tx_bytes;
108                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
109
110                 sum.rx_packets += tmp.rx_packets;
111                 sum.rx_bytes   += tmp.rx_bytes;
112                 sum.tx_packets += tmp.tx_packets;
113                 sum.tx_bytes   += tmp.tx_bytes;
114         }
115         dev->stats.rx_packets = sum.rx_packets;
116         dev->stats.rx_bytes   = sum.rx_bytes;
117         dev->stats.tx_packets = sum.tx_packets;
118         dev->stats.tx_bytes   = sum.tx_bytes;
119         return &dev->stats;
120 }
121
122 /**
123  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
124  *   @remote: the address of the tunnel exit-point
125  *   @local: the address of the tunnel entry-point
126  *
127  * Return:
128  *   tunnel matching given end-points if found,
129  *   else fallback tunnel if its device is up,
130  *   else %NULL
131  **/
132
133 #define for_each_ip6_tunnel_rcu(start) \
134         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
135
136 static struct ip6_tnl *
137 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
138 {
139         unsigned int hash = HASH(remote, local);
140         struct ip6_tnl *t;
141         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
142         struct in6_addr any;
143
144         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
145                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
146                     ipv6_addr_equal(remote, &t->parms.raddr) &&
147                     (t->dev->flags & IFF_UP))
148                         return t;
149         }
150
151         memset(&any, 0, sizeof(any));
152         hash = HASH(&any, local);
153         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
154                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
155                     ipv6_addr_any(&t->parms.raddr) &&
156                     (t->dev->flags & IFF_UP))
157                         return t;
158         }
159
160         hash = HASH(remote, &any);
161         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
162                 if (ipv6_addr_equal(remote, &t->parms.raddr) &&
163                     ipv6_addr_any(&t->parms.laddr) &&
164                     (t->dev->flags & IFF_UP))
165                         return t;
166         }
167
168         t = rcu_dereference(ip6n->collect_md_tun);
169         if (t && t->dev->flags & IFF_UP)
170                 return t;
171
172         t = rcu_dereference(ip6n->tnls_wc[0]);
173         if (t && (t->dev->flags & IFF_UP))
174                 return t;
175
176         return NULL;
177 }
178
179 /**
180  * ip6_tnl_bucket - get head of list matching given tunnel parameters
181  *   @p: parameters containing tunnel end-points
182  *
183  * Description:
184  *   ip6_tnl_bucket() returns the head of the list matching the
185  *   &struct in6_addr entries laddr and raddr in @p.
186  *
187  * Return: head of IPv6 tunnel list
188  **/
189
190 static struct ip6_tnl __rcu **
191 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
192 {
193         const struct in6_addr *remote = &p->raddr;
194         const struct in6_addr *local = &p->laddr;
195         unsigned int h = 0;
196         int prio = 0;
197
198         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
199                 prio = 1;
200                 h = HASH(remote, local);
201         }
202         return &ip6n->tnls[prio][h];
203 }
204
205 /**
206  * ip6_tnl_link - add tunnel to hash table
207  *   @t: tunnel to be added
208  **/
209
210 static void
211 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
212 {
213         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
214
215         if (t->parms.collect_md)
216                 rcu_assign_pointer(ip6n->collect_md_tun, t);
217         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
218         rcu_assign_pointer(*tp, t);
219 }
220
221 /**
222  * ip6_tnl_unlink - remove tunnel from hash table
223  *   @t: tunnel to be removed
224  **/
225
226 static void
227 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
228 {
229         struct ip6_tnl __rcu **tp;
230         struct ip6_tnl *iter;
231
232         if (t->parms.collect_md)
233                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
234
235         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
236              (iter = rtnl_dereference(*tp)) != NULL;
237              tp = &iter->next) {
238                 if (t == iter) {
239                         rcu_assign_pointer(*tp, t->next);
240                         break;
241                 }
242         }
243 }
244
245 static void ip6_dev_free(struct net_device *dev)
246 {
247         struct ip6_tnl *t = netdev_priv(dev);
248
249         gro_cells_destroy(&t->gro_cells);
250         dst_cache_destroy(&t->dst_cache);
251         free_percpu(dev->tstats);
252 }
253
254 static int ip6_tnl_create2(struct net_device *dev)
255 {
256         struct ip6_tnl *t = netdev_priv(dev);
257         struct net *net = dev_net(dev);
258         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
259         int err;
260
261         t = netdev_priv(dev);
262
263         dev->rtnl_link_ops = &ip6_link_ops;
264         err = register_netdevice(dev);
265         if (err < 0)
266                 goto out;
267
268         strcpy(t->parms.name, dev->name);
269
270         dev_hold(dev);
271         ip6_tnl_link(ip6n, t);
272         return 0;
273
274 out:
275         return err;
276 }
277
278 /**
279  * ip6_tnl_create - create a new tunnel
280  *   @p: tunnel parameters
281  *   @pt: pointer to new tunnel
282  *
283  * Description:
284  *   Create tunnel matching given parameters.
285  *
286  * Return:
287  *   created tunnel or error pointer
288  **/
289
290 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
291 {
292         struct net_device *dev;
293         struct ip6_tnl *t;
294         char name[IFNAMSIZ];
295         int err = -E2BIG;
296
297         if (p->name[0]) {
298                 if (!dev_valid_name(p->name))
299                         goto failed;
300                 strlcpy(name, p->name, IFNAMSIZ);
301         } else {
302                 sprintf(name, "ip6tnl%%d");
303         }
304         err = -ENOMEM;
305         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
306                            ip6_tnl_dev_setup);
307         if (!dev)
308                 goto failed;
309
310         dev_net_set(dev, net);
311
312         t = netdev_priv(dev);
313         t->parms = *p;
314         t->net = dev_net(dev);
315         err = ip6_tnl_create2(dev);
316         if (err < 0)
317                 goto failed_free;
318
319         return t;
320
321 failed_free:
322         free_netdev(dev);
323 failed:
324         return ERR_PTR(err);
325 }
326
327 /**
328  * ip6_tnl_locate - find or create tunnel matching given parameters
329  *   @p: tunnel parameters
330  *   @create: != 0 if allowed to create new tunnel if no match found
331  *
332  * Description:
333  *   ip6_tnl_locate() first tries to locate an existing tunnel
334  *   based on @parms. If this is unsuccessful, but @create is set a new
335  *   tunnel device is created and registered for use.
336  *
337  * Return:
338  *   matching tunnel or error pointer
339  **/
340
341 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
342                 struct __ip6_tnl_parm *p, int create)
343 {
344         const struct in6_addr *remote = &p->raddr;
345         const struct in6_addr *local = &p->laddr;
346         struct ip6_tnl __rcu **tp;
347         struct ip6_tnl *t;
348         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
349
350         for (tp = ip6_tnl_bucket(ip6n, p);
351              (t = rtnl_dereference(*tp)) != NULL;
352              tp = &t->next) {
353                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
354                     ipv6_addr_equal(remote, &t->parms.raddr)) {
355                         if (create)
356                                 return ERR_PTR(-EEXIST);
357
358                         return t;
359                 }
360         }
361         if (!create)
362                 return ERR_PTR(-ENODEV);
363         return ip6_tnl_create(net, p);
364 }
365
366 /**
367  * ip6_tnl_dev_uninit - tunnel device uninitializer
368  *   @dev: the device to be destroyed
369  *
370  * Description:
371  *   ip6_tnl_dev_uninit() removes tunnel from its list
372  **/
373
374 static void
375 ip6_tnl_dev_uninit(struct net_device *dev)
376 {
377         struct ip6_tnl *t = netdev_priv(dev);
378         struct net *net = t->net;
379         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
380
381         if (dev == ip6n->fb_tnl_dev)
382                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
383         else
384                 ip6_tnl_unlink(ip6n, t);
385         dst_cache_reset(&t->dst_cache);
386         dev_put(dev);
387 }
388
389 /**
390  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
391  *   @skb: received socket buffer
392  *
393  * Return:
394  *   0 if none was found,
395  *   else index to encapsulation limit
396  **/
397
398 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
399 {
400         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
401         unsigned int nhoff = raw - skb->data;
402         unsigned int off = nhoff + sizeof(*ipv6h);
403         u8 next, nexthdr = ipv6h->nexthdr;
404
405         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
406                 struct ipv6_opt_hdr *hdr;
407                 u16 optlen;
408
409                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
410                         break;
411
412                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
413                 if (nexthdr == NEXTHDR_FRAGMENT) {
414                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
415                         if (frag_hdr->frag_off)
416                                 break;
417                         optlen = 8;
418                 } else if (nexthdr == NEXTHDR_AUTH) {
419                         optlen = (hdr->hdrlen + 2) << 2;
420                 } else {
421                         optlen = ipv6_optlen(hdr);
422                 }
423                 /* cache hdr->nexthdr, since pskb_may_pull() might
424                  * invalidate hdr
425                  */
426                 next = hdr->nexthdr;
427                 if (nexthdr == NEXTHDR_DEST) {
428                         u16 i = 2;
429
430                         /* Remember : hdr is no longer valid at this point. */
431                         if (!pskb_may_pull(skb, off + optlen))
432                                 break;
433
434                         while (1) {
435                                 struct ipv6_tlv_tnl_enc_lim *tel;
436
437                                 /* No more room for encapsulation limit */
438                                 if (i + sizeof(*tel) > optlen)
439                                         break;
440
441                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
442                                 /* return index of option if found and valid */
443                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
444                                     tel->length == 1)
445                                         return i + off - nhoff;
446                                 /* else jump to next option */
447                                 if (tel->type)
448                                         i += tel->length + 2;
449                                 else
450                                         i++;
451                         }
452                 }
453                 nexthdr = next;
454                 off += optlen;
455         }
456         return 0;
457 }
458 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
459
460 /**
461  * ip6_tnl_err - tunnel error handler
462  *
463  * Description:
464  *   ip6_tnl_err() should handle errors in the tunnel according
465  *   to the specifications in RFC 2473.
466  **/
467
468 static int
469 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
470             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
471 {
472         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
473         struct net *net = dev_net(skb->dev);
474         u8 rel_type = ICMPV6_DEST_UNREACH;
475         u8 rel_code = ICMPV6_ADDR_UNREACH;
476         __u32 rel_info = 0;
477         struct ip6_tnl *t;
478         int err = -ENOENT;
479         int rel_msg = 0;
480         u8 tproto;
481         __u16 len;
482
483         /* If the packet doesn't contain the original IPv6 header we are
484            in trouble since we might need the source address for further
485            processing of the error. */
486
487         rcu_read_lock();
488         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
489         if (!t)
490                 goto out;
491
492         tproto = READ_ONCE(t->parms.proto);
493         if (tproto != ipproto && tproto != 0)
494                 goto out;
495
496         err = 0;
497
498         switch (*type) {
499                 struct ipv6_tlv_tnl_enc_lim *tel;
500                 __u32 mtu, teli;
501         case ICMPV6_DEST_UNREACH:
502                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
503                                     t->parms.name);
504                 rel_msg = 1;
505                 break;
506         case ICMPV6_TIME_EXCEED:
507                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
508                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
509                                             t->parms.name);
510                         rel_msg = 1;
511                 }
512                 break;
513         case ICMPV6_PARAMPROB:
514                 teli = 0;
515                 if ((*code) == ICMPV6_HDR_FIELD)
516                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
517
518                 if (teli && teli == *info - 2) {
519                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
520                         if (tel->encap_limit == 0) {
521                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
522                                                     t->parms.name);
523                                 rel_msg = 1;
524                         }
525                 } else {
526                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
527                                             t->parms.name);
528                 }
529                 break;
530         case ICMPV6_PKT_TOOBIG:
531                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
532                                 sock_net_uid(net, NULL));
533                 mtu = *info - offset;
534                 if (mtu < IPV6_MIN_MTU)
535                         mtu = IPV6_MIN_MTU;
536                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
537                 if (len > mtu) {
538                         rel_type = ICMPV6_PKT_TOOBIG;
539                         rel_code = 0;
540                         rel_info = mtu;
541                         rel_msg = 1;
542                 }
543                 break;
544         case NDISC_REDIRECT:
545                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
546                              sock_net_uid(net, NULL));
547                 break;
548         }
549
550         *type = rel_type;
551         *code = rel_code;
552         *info = rel_info;
553         *msg = rel_msg;
554
555 out:
556         rcu_read_unlock();
557         return err;
558 }
559
560 static int
561 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
562            u8 type, u8 code, int offset, __be32 info)
563 {
564         __u32 rel_info = ntohl(info);
565         const struct iphdr *eiph;
566         struct sk_buff *skb2;
567         int err, rel_msg = 0;
568         u8 rel_type = type;
569         u8 rel_code = code;
570         struct rtable *rt;
571         struct flowi4 fl4;
572
573         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
574                           &rel_msg, &rel_info, offset);
575         if (err < 0)
576                 return err;
577
578         if (rel_msg == 0)
579                 return 0;
580
581         switch (rel_type) {
582         case ICMPV6_DEST_UNREACH:
583                 if (rel_code != ICMPV6_ADDR_UNREACH)
584                         return 0;
585                 rel_type = ICMP_DEST_UNREACH;
586                 rel_code = ICMP_HOST_UNREACH;
587                 break;
588         case ICMPV6_PKT_TOOBIG:
589                 if (rel_code != 0)
590                         return 0;
591                 rel_type = ICMP_DEST_UNREACH;
592                 rel_code = ICMP_FRAG_NEEDED;
593                 break;
594         default:
595                 return 0;
596         }
597
598         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
599                 return 0;
600
601         skb2 = skb_clone(skb, GFP_ATOMIC);
602         if (!skb2)
603                 return 0;
604
605         skb_dst_drop(skb2);
606
607         skb_pull(skb2, offset);
608         skb_reset_network_header(skb2);
609         eiph = ip_hdr(skb2);
610
611         /* Try to guess incoming interface */
612         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
613                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
614         if (IS_ERR(rt))
615                 goto out;
616
617         skb2->dev = rt->dst.dev;
618         ip_rt_put(rt);
619
620         /* route "incoming" packet */
621         if (rt->rt_flags & RTCF_LOCAL) {
622                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
623                                            eiph->daddr, eiph->saddr, 0, 0,
624                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
625                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
626                         if (!IS_ERR(rt))
627                                 ip_rt_put(rt);
628                         goto out;
629                 }
630                 skb_dst_set(skb2, &rt->dst);
631         } else {
632                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
633                                    skb2->dev) ||
634                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
635                         goto out;
636         }
637
638         /* change mtu on this route */
639         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
640                 if (rel_info > dst_mtu(skb_dst(skb2)))
641                         goto out;
642
643                 skb_dst_update_pmtu(skb2, rel_info);
644         }
645
646         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
647
648 out:
649         kfree_skb(skb2);
650         return 0;
651 }
652
653 static int
654 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
655            u8 type, u8 code, int offset, __be32 info)
656 {
657         __u32 rel_info = ntohl(info);
658         int err, rel_msg = 0;
659         u8 rel_type = type;
660         u8 rel_code = code;
661
662         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
663                           &rel_msg, &rel_info, offset);
664         if (err < 0)
665                 return err;
666
667         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
668                 struct rt6_info *rt;
669                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
670
671                 if (!skb2)
672                         return 0;
673
674                 skb_dst_drop(skb2);
675                 skb_pull(skb2, offset);
676                 skb_reset_network_header(skb2);
677
678                 /* Try to guess incoming interface */
679                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
680                                 NULL, 0, skb2, 0);
681
682                 if (rt && rt->dst.dev)
683                         skb2->dev = rt->dst.dev;
684
685                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
686
687                 ip6_rt_put(rt);
688
689                 kfree_skb(skb2);
690         }
691
692         return 0;
693 }
694
695 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
696                                        const struct ipv6hdr *ipv6h,
697                                        struct sk_buff *skb)
698 {
699         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
700
701         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
702                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
703
704         return IP6_ECN_decapsulate(ipv6h, skb);
705 }
706
707 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
708                                        const struct ipv6hdr *ipv6h,
709                                        struct sk_buff *skb)
710 {
711         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
712                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
713
714         return IP6_ECN_decapsulate(ipv6h, skb);
715 }
716
717 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
718                              const struct in6_addr *laddr,
719                              const struct in6_addr *raddr)
720 {
721         struct __ip6_tnl_parm *p = &t->parms;
722         int ltype = ipv6_addr_type(laddr);
723         int rtype = ipv6_addr_type(raddr);
724         __u32 flags = 0;
725
726         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
727                 flags = IP6_TNL_F_CAP_PER_PACKET;
728         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
729                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
730                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
731                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
732                 if (ltype&IPV6_ADDR_UNICAST)
733                         flags |= IP6_TNL_F_CAP_XMIT;
734                 if (rtype&IPV6_ADDR_UNICAST)
735                         flags |= IP6_TNL_F_CAP_RCV;
736         }
737         return flags;
738 }
739 EXPORT_SYMBOL(ip6_tnl_get_cap);
740
741 /* called with rcu_read_lock() */
742 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
743                                   const struct in6_addr *laddr,
744                                   const struct in6_addr *raddr)
745 {
746         struct __ip6_tnl_parm *p = &t->parms;
747         int ret = 0;
748         struct net *net = t->net;
749
750         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
751             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
752              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
753                 struct net_device *ldev = NULL;
754
755                 if (p->link)
756                         ldev = dev_get_by_index_rcu(net, p->link);
757
758                 if ((ipv6_addr_is_multicast(laddr) ||
759                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
760                                                     0, IFA_F_TENTATIVE))) &&
761                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
762                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
763                                                      0, IFA_F_TENTATIVE))))
764                         ret = 1;
765         }
766         return ret;
767 }
768 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
769
770 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
771                          const struct tnl_ptk_info *tpi,
772                          struct metadata_dst *tun_dst,
773                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
774                                                 const struct ipv6hdr *ipv6h,
775                                                 struct sk_buff *skb),
776                          bool log_ecn_err)
777 {
778         struct pcpu_sw_netstats *tstats;
779         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
780         int err;
781
782         if ((!(tpi->flags & TUNNEL_CSUM) &&
783              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
784             ((tpi->flags & TUNNEL_CSUM) &&
785              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
786                 tunnel->dev->stats.rx_crc_errors++;
787                 tunnel->dev->stats.rx_errors++;
788                 goto drop;
789         }
790
791         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
792                 if (!(tpi->flags & TUNNEL_SEQ) ||
793                     (tunnel->i_seqno &&
794                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
795                         tunnel->dev->stats.rx_fifo_errors++;
796                         tunnel->dev->stats.rx_errors++;
797                         goto drop;
798                 }
799                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
800         }
801
802         skb->protocol = tpi->proto;
803
804         /* Warning: All skb pointers will be invalidated! */
805         if (tunnel->dev->type == ARPHRD_ETHER) {
806                 if (!pskb_may_pull(skb, ETH_HLEN)) {
807                         tunnel->dev->stats.rx_length_errors++;
808                         tunnel->dev->stats.rx_errors++;
809                         goto drop;
810                 }
811
812                 ipv6h = ipv6_hdr(skb);
813                 skb->protocol = eth_type_trans(skb, tunnel->dev);
814                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
815         } else {
816                 skb->dev = tunnel->dev;
817         }
818
819         skb_reset_network_header(skb);
820         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
821
822         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
823
824         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
825         if (unlikely(err)) {
826                 if (log_ecn_err)
827                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
828                                              &ipv6h->saddr,
829                                              ipv6_get_dsfield(ipv6h));
830                 if (err > 1) {
831                         ++tunnel->dev->stats.rx_frame_errors;
832                         ++tunnel->dev->stats.rx_errors;
833                         goto drop;
834                 }
835         }
836
837         tstats = this_cpu_ptr(tunnel->dev->tstats);
838         u64_stats_update_begin(&tstats->syncp);
839         tstats->rx_packets++;
840         tstats->rx_bytes += skb->len;
841         u64_stats_update_end(&tstats->syncp);
842
843         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
844
845         if (tun_dst)
846                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
847
848         gro_cells_receive(&tunnel->gro_cells, skb);
849         return 0;
850
851 drop:
852         if (tun_dst)
853                 dst_release((struct dst_entry *)tun_dst);
854         kfree_skb(skb);
855         return 0;
856 }
857
858 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
859                 const struct tnl_ptk_info *tpi,
860                 struct metadata_dst *tun_dst,
861                 bool log_ecn_err)
862 {
863         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,
864                              log_ecn_err);
865 }
866 EXPORT_SYMBOL(ip6_tnl_rcv);
867
868 static const struct tnl_ptk_info tpi_v6 = {
869         /* no tunnel info required for ipxip6. */
870         .proto = htons(ETH_P_IPV6),
871 };
872
873 static const struct tnl_ptk_info tpi_v4 = {
874         /* no tunnel info required for ipxip6. */
875         .proto = htons(ETH_P_IP),
876 };
877
878 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
879                       const struct tnl_ptk_info *tpi,
880                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
881                                                   const struct ipv6hdr *ipv6h,
882                                                   struct sk_buff *skb))
883 {
884         struct ip6_tnl *t;
885         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
886         struct metadata_dst *tun_dst = NULL;
887         int ret = -1;
888
889         rcu_read_lock();
890         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
891
892         if (t) {
893                 u8 tproto = READ_ONCE(t->parms.proto);
894
895                 if (tproto != ipproto && tproto != 0)
896                         goto drop;
897                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
898                         goto drop;
899                 ipv6h = ipv6_hdr(skb);
900                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
901                         goto drop;
902                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
903                         goto drop;
904                 if (t->parms.collect_md) {
905                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
906                         if (!tun_dst)
907                                 goto drop;
908                 }
909                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
910                                     log_ecn_error);
911         }
912
913         rcu_read_unlock();
914
915         return ret;
916
917 drop:
918         rcu_read_unlock();
919         kfree_skb(skb);
920         return 0;
921 }
922
923 static int ip4ip6_rcv(struct sk_buff *skb)
924 {
925         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
926                           ip4ip6_dscp_ecn_decapsulate);
927 }
928
929 static int ip6ip6_rcv(struct sk_buff *skb)
930 {
931         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
932                           ip6ip6_dscp_ecn_decapsulate);
933 }
934
935 struct ipv6_tel_txoption {
936         struct ipv6_txoptions ops;
937         __u8 dst_opt[8];
938 };
939
940 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
941 {
942         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
943
944         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
945         opt->dst_opt[3] = 1;
946         opt->dst_opt[4] = encap_limit;
947         opt->dst_opt[5] = IPV6_TLV_PADN;
948         opt->dst_opt[6] = 1;
949
950         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
951         opt->ops.opt_nflen = 8;
952 }
953
954 /**
955  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
956  *   @t: the outgoing tunnel device
957  *   @hdr: IPv6 header from the incoming packet
958  *
959  * Description:
960  *   Avoid trivial tunneling loop by checking that tunnel exit-point
961  *   doesn't match source of incoming packet.
962  *
963  * Return:
964  *   1 if conflict,
965  *   0 else
966  **/
967
968 static inline bool
969 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
970 {
971         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
972 }
973
974 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
975                      const struct in6_addr *laddr,
976                      const struct in6_addr *raddr)
977 {
978         struct __ip6_tnl_parm *p = &t->parms;
979         int ret = 0;
980         struct net *net = t->net;
981
982         if (t->parms.collect_md)
983                 return 1;
984
985         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
986             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
987              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
988                 struct net_device *ldev = NULL;
989
990                 rcu_read_lock();
991                 if (p->link)
992                         ldev = dev_get_by_index_rcu(net, p->link);
993
994                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
995                                                       0, IFA_F_TENTATIVE)))
996                         pr_warn("%s xmit: Local address not yet configured!\n",
997                                 p->name);
998                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
999                          !ipv6_addr_is_multicast(raddr) &&
1000                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1001                                                           true, 0, IFA_F_TENTATIVE)))
1002                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1003                                 p->name);
1004                 else
1005                         ret = 1;
1006                 rcu_read_unlock();
1007         }
1008         return ret;
1009 }
1010 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1011
1012 /**
1013  * ip6_tnl_xmit - encapsulate packet and send
1014  *   @skb: the outgoing socket buffer
1015  *   @dev: the outgoing tunnel device
1016  *   @dsfield: dscp code for outer header
1017  *   @fl6: flow of tunneled packet
1018  *   @encap_limit: encapsulation limit
1019  *   @pmtu: Path MTU is stored if packet is too big
1020  *   @proto: next header value
1021  *
1022  * Description:
1023  *   Build new header and do some sanity checks on the packet before sending
1024  *   it.
1025  *
1026  * Return:
1027  *   0 on success
1028  *   -1 fail
1029  *   %-EMSGSIZE message too big. return mtu in this case.
1030  **/
1031
1032 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1033                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1034                  __u8 proto)
1035 {
1036         struct ip6_tnl *t = netdev_priv(dev);
1037         struct net *net = t->net;
1038         struct net_device_stats *stats = &t->dev->stats;
1039         struct ipv6hdr *ipv6h;
1040         struct ipv6_tel_txoption opt;
1041         struct dst_entry *dst = NULL, *ndst = NULL;
1042         struct net_device *tdev;
1043         int mtu;
1044         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1045         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1046         unsigned int max_headroom = psh_hlen;
1047         bool use_cache = false;
1048         u8 hop_limit;
1049         int err = -1;
1050
1051         if (t->parms.collect_md) {
1052                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1053                 goto route_lookup;
1054         } else {
1055                 hop_limit = t->parms.hop_limit;
1056         }
1057
1058         /* NBMA tunnel */
1059         if (ipv6_addr_any(&t->parms.raddr)) {
1060                 if (skb->protocol == htons(ETH_P_IPV6)) {
1061                         struct in6_addr *addr6;
1062                         struct neighbour *neigh;
1063                         int addr_type;
1064
1065                         if (!skb_dst(skb))
1066                                 goto tx_err_link_failure;
1067
1068                         neigh = dst_neigh_lookup(skb_dst(skb),
1069                                                  &ipv6_hdr(skb)->daddr);
1070                         if (!neigh)
1071                                 goto tx_err_link_failure;
1072
1073                         addr6 = (struct in6_addr *)&neigh->primary_key;
1074                         addr_type = ipv6_addr_type(addr6);
1075
1076                         if (addr_type == IPV6_ADDR_ANY)
1077                                 addr6 = &ipv6_hdr(skb)->daddr;
1078
1079                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1080                         neigh_release(neigh);
1081                 }
1082         } else if (t->parms.proto != 0 && !(t->parms.flags &
1083                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1084                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1085                 /* enable the cache only if neither the outer protocol nor the
1086                  * routing decision depends on the current inner header value
1087                  */
1088                 use_cache = true;
1089         }
1090
1091         if (use_cache)
1092                 dst = dst_cache_get(&t->dst_cache);
1093
1094         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1095                 goto tx_err_link_failure;
1096
1097         if (!dst) {
1098 route_lookup:
1099                 /* add dsfield to flowlabel for route lookup */
1100                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1101
1102                 dst = ip6_route_output(net, NULL, fl6);
1103
1104                 if (dst->error)
1105                         goto tx_err_link_failure;
1106                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1107                 if (IS_ERR(dst)) {
1108                         err = PTR_ERR(dst);
1109                         dst = NULL;
1110                         goto tx_err_link_failure;
1111                 }
1112                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1113                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1114                                        &fl6->daddr, 0, &fl6->saddr))
1115                         goto tx_err_link_failure;
1116                 ndst = dst;
1117         }
1118
1119         tdev = dst->dev;
1120
1121         if (tdev == dev) {
1122                 stats->collisions++;
1123                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1124                                      t->parms.name);
1125                 goto tx_err_dst_release;
1126         }
1127         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1128         if (encap_limit >= 0) {
1129                 max_headroom += 8;
1130                 mtu -= 8;
1131         }
1132         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1133                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1134
1135         skb_dst_update_pmtu(skb, mtu);
1136         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1137                 *pmtu = mtu;
1138                 err = -EMSGSIZE;
1139                 goto tx_err_dst_release;
1140         }
1141
1142         if (t->err_count > 0) {
1143                 if (time_before(jiffies,
1144                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1145                         t->err_count--;
1146
1147                         dst_link_failure(skb);
1148                 } else {
1149                         t->err_count = 0;
1150                 }
1151         }
1152
1153         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1154
1155         /*
1156          * Okay, now see if we can stuff it in the buffer as-is.
1157          */
1158         max_headroom += LL_RESERVED_SPACE(tdev);
1159
1160         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1161             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1162                 struct sk_buff *new_skb;
1163
1164                 new_skb = skb_realloc_headroom(skb, max_headroom);
1165                 if (!new_skb)
1166                         goto tx_err_dst_release;
1167
1168                 if (skb->sk)
1169                         skb_set_owner_w(new_skb, skb->sk);
1170                 consume_skb(skb);
1171                 skb = new_skb;
1172         }
1173
1174         if (t->parms.collect_md) {
1175                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1176                         goto tx_err_dst_release;
1177         } else {
1178                 if (use_cache && ndst)
1179                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1180         }
1181         skb_dst_set(skb, dst);
1182
1183         if (hop_limit == 0) {
1184                 if (skb->protocol == htons(ETH_P_IP))
1185                         hop_limit = ip_hdr(skb)->ttl;
1186                 else if (skb->protocol == htons(ETH_P_IPV6))
1187                         hop_limit = ipv6_hdr(skb)->hop_limit;
1188                 else
1189                         hop_limit = ip6_dst_hoplimit(dst);
1190         }
1191
1192         /* Calculate max headroom for all the headers and adjust
1193          * needed_headroom if necessary.
1194          */
1195         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1196                         + dst->header_len + t->hlen;
1197         if (max_headroom > dev->needed_headroom)
1198                 dev->needed_headroom = max_headroom;
1199
1200         err = ip6_tnl_encap(skb, t, &proto, fl6);
1201         if (err)
1202                 return err;
1203
1204         if (encap_limit >= 0) {
1205                 init_tel_txopt(&opt, encap_limit);
1206                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1207         }
1208
1209         skb_push(skb, sizeof(struct ipv6hdr));
1210         skb_reset_network_header(skb);
1211         ipv6h = ipv6_hdr(skb);
1212         ip6_flow_hdr(ipv6h, dsfield,
1213                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1214         ipv6h->hop_limit = hop_limit;
1215         ipv6h->nexthdr = proto;
1216         ipv6h->saddr = fl6->saddr;
1217         ipv6h->daddr = fl6->daddr;
1218         ip6tunnel_xmit(NULL, skb, dev);
1219         return 0;
1220 tx_err_link_failure:
1221         stats->tx_carrier_errors++;
1222         dst_link_failure(skb);
1223 tx_err_dst_release:
1224         dst_release(dst);
1225         return err;
1226 }
1227 EXPORT_SYMBOL(ip6_tnl_xmit);
1228
1229 static inline int
1230 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1231 {
1232         struct ip6_tnl *t = netdev_priv(dev);
1233         const struct iphdr  *iph;
1234         int encap_limit = -1;
1235         struct flowi6 fl6;
1236         __u8 dsfield;
1237         __u32 mtu;
1238         u8 tproto;
1239         int err;
1240
1241         iph = ip_hdr(skb);
1242         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1243
1244         tproto = READ_ONCE(t->parms.proto);
1245         if (tproto != IPPROTO_IPIP && tproto != 0)
1246                 return -1;
1247
1248         if (t->parms.collect_md) {
1249                 struct ip_tunnel_info *tun_info;
1250                 const struct ip_tunnel_key *key;
1251
1252                 tun_info = skb_tunnel_info(skb);
1253                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1254                              ip_tunnel_info_af(tun_info) != AF_INET6))
1255                         return -1;
1256                 key = &tun_info->key;
1257                 memset(&fl6, 0, sizeof(fl6));
1258                 fl6.flowi6_proto = IPPROTO_IPIP;
1259                 fl6.saddr = key->u.ipv6.src;
1260                 fl6.daddr = key->u.ipv6.dst;
1261                 fl6.flowlabel = key->label;
1262                 dsfield =  key->tos;
1263         } else {
1264                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1265                         encap_limit = t->parms.encap_limit;
1266
1267                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1268                 fl6.flowi6_proto = IPPROTO_IPIP;
1269
1270                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1271                         dsfield = ipv4_get_dsfield(iph);
1272                 else
1273                         dsfield = ip6_tclass(t->parms.flowinfo);
1274                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1275                         fl6.flowi6_mark = skb->mark;
1276                 else
1277                         fl6.flowi6_mark = t->parms.fwmark;
1278         }
1279
1280         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1281
1282         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1283                 return -1;
1284
1285         dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1286
1287         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1288
1289         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1290                            IPPROTO_IPIP);
1291         if (err != 0) {
1292                 /* XXX: send ICMP error even if DF is not set. */
1293                 if (err == -EMSGSIZE)
1294                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1295                                   htonl(mtu));
1296                 return -1;
1297         }
1298
1299         return 0;
1300 }
1301
1302 static inline int
1303 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1304 {
1305         struct ip6_tnl *t = netdev_priv(dev);
1306         struct ipv6hdr *ipv6h;
1307         int encap_limit = -1;
1308         __u16 offset;
1309         struct flowi6 fl6;
1310         __u8 dsfield;
1311         __u32 mtu;
1312         u8 tproto;
1313         int err;
1314
1315         ipv6h = ipv6_hdr(skb);
1316         tproto = READ_ONCE(t->parms.proto);
1317         if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1318             ip6_tnl_addr_conflict(t, ipv6h))
1319                 return -1;
1320
1321         if (t->parms.collect_md) {
1322                 struct ip_tunnel_info *tun_info;
1323                 const struct ip_tunnel_key *key;
1324
1325                 tun_info = skb_tunnel_info(skb);
1326                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1327                              ip_tunnel_info_af(tun_info) != AF_INET6))
1328                         return -1;
1329                 key = &tun_info->key;
1330                 memset(&fl6, 0, sizeof(fl6));
1331                 fl6.flowi6_proto = IPPROTO_IPV6;
1332                 fl6.saddr = key->u.ipv6.src;
1333                 fl6.daddr = key->u.ipv6.dst;
1334                 fl6.flowlabel = key->label;
1335                 dsfield = key->tos;
1336         } else {
1337                 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1338                 /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1339                 ipv6h = ipv6_hdr(skb);
1340                 if (offset > 0) {
1341                         struct ipv6_tlv_tnl_enc_lim *tel;
1342
1343                         tel = (void *)&skb_network_header(skb)[offset];
1344                         if (tel->encap_limit == 0) {
1345                                 icmpv6_send(skb, ICMPV6_PARAMPROB,
1346                                             ICMPV6_HDR_FIELD, offset + 2);
1347                                 return -1;
1348                         }
1349                         encap_limit = tel->encap_limit - 1;
1350                 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1351                         encap_limit = t->parms.encap_limit;
1352                 }
1353
1354                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1355                 fl6.flowi6_proto = IPPROTO_IPV6;
1356
1357                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1358                         dsfield = ipv6_get_dsfield(ipv6h);
1359                 else
1360                         dsfield = ip6_tclass(t->parms.flowinfo);
1361                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1362                         fl6.flowlabel |= ip6_flowlabel(ipv6h);
1363                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1364                         fl6.flowi6_mark = skb->mark;
1365                 else
1366                         fl6.flowi6_mark = t->parms.fwmark;
1367         }
1368
1369         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1370
1371         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1372                 return -1;
1373
1374         dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1375
1376         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1377
1378         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1379                            IPPROTO_IPV6);
1380         if (err != 0) {
1381                 if (err == -EMSGSIZE)
1382                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1383                 return -1;
1384         }
1385
1386         return 0;
1387 }
1388
1389 static netdev_tx_t
1390 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1391 {
1392         struct ip6_tnl *t = netdev_priv(dev);
1393         struct net_device_stats *stats = &t->dev->stats;
1394         int ret;
1395
1396         if (!pskb_inet_may_pull(skb))
1397                 goto tx_err;
1398
1399         switch (skb->protocol) {
1400         case htons(ETH_P_IP):
1401                 ret = ip4ip6_tnl_xmit(skb, dev);
1402                 break;
1403         case htons(ETH_P_IPV6):
1404                 ret = ip6ip6_tnl_xmit(skb, dev);
1405                 break;
1406         default:
1407                 goto tx_err;
1408         }
1409
1410         if (ret < 0)
1411                 goto tx_err;
1412
1413         return NETDEV_TX_OK;
1414
1415 tx_err:
1416         stats->tx_errors++;
1417         stats->tx_dropped++;
1418         kfree_skb(skb);
1419         return NETDEV_TX_OK;
1420 }
1421
1422 static void ip6_tnl_link_config(struct ip6_tnl *t)
1423 {
1424         struct net_device *dev = t->dev;
1425         struct __ip6_tnl_parm *p = &t->parms;
1426         struct flowi6 *fl6 = &t->fl.u.ip6;
1427         int t_hlen;
1428
1429         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1430         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1431
1432         /* Set up flowi template */
1433         fl6->saddr = p->laddr;
1434         fl6->daddr = p->raddr;
1435         fl6->flowi6_oif = p->link;
1436         fl6->flowlabel = 0;
1437
1438         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1439                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1440         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1441                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1442
1443         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1444         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1445
1446         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1447                 dev->flags |= IFF_POINTOPOINT;
1448         else
1449                 dev->flags &= ~IFF_POINTOPOINT;
1450
1451         t->tun_hlen = 0;
1452         t->hlen = t->encap_hlen + t->tun_hlen;
1453         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1454
1455         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1456                 int strict = (ipv6_addr_type(&p->raddr) &
1457                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1458
1459                 struct rt6_info *rt = rt6_lookup(t->net,
1460                                                  &p->raddr, &p->laddr,
1461                                                  p->link, NULL, strict);
1462
1463                 if (!rt)
1464                         return;
1465
1466                 if (rt->dst.dev) {
1467                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1468                                 t_hlen;
1469
1470                         dev->mtu = rt->dst.dev->mtu - t_hlen;
1471                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1472                                 dev->mtu -= 8;
1473
1474                         if (dev->mtu < IPV6_MIN_MTU)
1475                                 dev->mtu = IPV6_MIN_MTU;
1476                 }
1477                 ip6_rt_put(rt);
1478         }
1479 }
1480
1481 /**
1482  * ip6_tnl_change - update the tunnel parameters
1483  *   @t: tunnel to be changed
1484  *   @p: tunnel configuration parameters
1485  *
1486  * Description:
1487  *   ip6_tnl_change() updates the tunnel parameters
1488  **/
1489
1490 static int
1491 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1492 {
1493         t->parms.laddr = p->laddr;
1494         t->parms.raddr = p->raddr;
1495         t->parms.flags = p->flags;
1496         t->parms.hop_limit = p->hop_limit;
1497         t->parms.encap_limit = p->encap_limit;
1498         t->parms.flowinfo = p->flowinfo;
1499         t->parms.link = p->link;
1500         t->parms.proto = p->proto;
1501         t->parms.fwmark = p->fwmark;
1502         dst_cache_reset(&t->dst_cache);
1503         ip6_tnl_link_config(t);
1504         return 0;
1505 }
1506
1507 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1508 {
1509         struct net *net = t->net;
1510         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1511         int err;
1512
1513         ip6_tnl_unlink(ip6n, t);
1514         synchronize_net();
1515         err = ip6_tnl_change(t, p);
1516         ip6_tnl_link(ip6n, t);
1517         netdev_state_change(t->dev);
1518         return err;
1519 }
1520
1521 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1522 {
1523         /* for default tnl0 device allow to change only the proto */
1524         t->parms.proto = p->proto;
1525         netdev_state_change(t->dev);
1526         return 0;
1527 }
1528
1529 static void
1530 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1531 {
1532         p->laddr = u->laddr;
1533         p->raddr = u->raddr;
1534         p->flags = u->flags;
1535         p->hop_limit = u->hop_limit;
1536         p->encap_limit = u->encap_limit;
1537         p->flowinfo = u->flowinfo;
1538         p->link = u->link;
1539         p->proto = u->proto;
1540         memcpy(p->name, u->name, sizeof(u->name));
1541 }
1542
1543 static void
1544 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1545 {
1546         u->laddr = p->laddr;
1547         u->raddr = p->raddr;
1548         u->flags = p->flags;
1549         u->hop_limit = p->hop_limit;
1550         u->encap_limit = p->encap_limit;
1551         u->flowinfo = p->flowinfo;
1552         u->link = p->link;
1553         u->proto = p->proto;
1554         memcpy(u->name, p->name, sizeof(u->name));
1555 }
1556
1557 /**
1558  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1559  *   @dev: virtual device associated with tunnel
1560  *   @ifr: parameters passed from userspace
1561  *   @cmd: command to be performed
1562  *
1563  * Description:
1564  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1565  *   from userspace.
1566  *
1567  *   The possible commands are the following:
1568  *     %SIOCGETTUNNEL: get tunnel parameters for device
1569  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1570  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1571  *     %SIOCDELTUNNEL: delete tunnel
1572  *
1573  *   The fallback device "ip6tnl0", created during module
1574  *   initialization, can be used for creating other tunnel devices.
1575  *
1576  * Return:
1577  *   0 on success,
1578  *   %-EFAULT if unable to copy data to or from userspace,
1579  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1580  *   %-EINVAL if passed tunnel parameters are invalid,
1581  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1582  *   %-ENODEV if attempting to change or delete a nonexisting device
1583  **/
1584
1585 static int
1586 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1587 {
1588         int err = 0;
1589         struct ip6_tnl_parm p;
1590         struct __ip6_tnl_parm p1;
1591         struct ip6_tnl *t = netdev_priv(dev);
1592         struct net *net = t->net;
1593         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1594
1595         memset(&p1, 0, sizeof(p1));
1596
1597         switch (cmd) {
1598         case SIOCGETTUNNEL:
1599                 if (dev == ip6n->fb_tnl_dev) {
1600                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1601                                 err = -EFAULT;
1602                                 break;
1603                         }
1604                         ip6_tnl_parm_from_user(&p1, &p);
1605                         t = ip6_tnl_locate(net, &p1, 0);
1606                         if (IS_ERR(t))
1607                                 t = netdev_priv(dev);
1608                 } else {
1609                         memset(&p, 0, sizeof(p));
1610                 }
1611                 ip6_tnl_parm_to_user(&p, &t->parms);
1612                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1613                         err = -EFAULT;
1614                 }
1615                 break;
1616         case SIOCADDTUNNEL:
1617         case SIOCCHGTUNNEL:
1618                 err = -EPERM;
1619                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1620                         break;
1621                 err = -EFAULT;
1622                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1623                         break;
1624                 err = -EINVAL;
1625                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1626                     p.proto != 0)
1627                         break;
1628                 ip6_tnl_parm_from_user(&p1, &p);
1629                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1630                 if (cmd == SIOCCHGTUNNEL) {
1631                         if (!IS_ERR(t)) {
1632                                 if (t->dev != dev) {
1633                                         err = -EEXIST;
1634                                         break;
1635                                 }
1636                         } else
1637                                 t = netdev_priv(dev);
1638                         if (dev == ip6n->fb_tnl_dev)
1639                                 err = ip6_tnl0_update(t, &p1);
1640                         else
1641                                 err = ip6_tnl_update(t, &p1);
1642                 }
1643                 if (!IS_ERR(t)) {
1644                         err = 0;
1645                         ip6_tnl_parm_to_user(&p, &t->parms);
1646                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1647                                 err = -EFAULT;
1648
1649                 } else {
1650                         err = PTR_ERR(t);
1651                 }
1652                 break;
1653         case SIOCDELTUNNEL:
1654                 err = -EPERM;
1655                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1656                         break;
1657
1658                 if (dev == ip6n->fb_tnl_dev) {
1659                         err = -EFAULT;
1660                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1661                                 break;
1662                         err = -ENOENT;
1663                         ip6_tnl_parm_from_user(&p1, &p);
1664                         t = ip6_tnl_locate(net, &p1, 0);
1665                         if (IS_ERR(t))
1666                                 break;
1667                         err = -EPERM;
1668                         if (t->dev == ip6n->fb_tnl_dev)
1669                                 break;
1670                         dev = t->dev;
1671                 }
1672                 err = 0;
1673                 unregister_netdevice(dev);
1674                 break;
1675         default:
1676                 err = -EINVAL;
1677         }
1678         return err;
1679 }
1680
1681 /**
1682  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1683  *   @dev: virtual device associated with tunnel
1684  *   @new_mtu: the new mtu
1685  *
1686  * Return:
1687  *   0 on success,
1688  *   %-EINVAL if mtu too small
1689  **/
1690
1691 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1692 {
1693         struct ip6_tnl *tnl = netdev_priv(dev);
1694
1695         if (tnl->parms.proto == IPPROTO_IPV6) {
1696                 if (new_mtu < IPV6_MIN_MTU)
1697                         return -EINVAL;
1698         } else {
1699                 if (new_mtu < ETH_MIN_MTU)
1700                         return -EINVAL;
1701         }
1702         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1703                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1704                         return -EINVAL;
1705         } else {
1706                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1707                         return -EINVAL;
1708         }
1709         dev->mtu = new_mtu;
1710         return 0;
1711 }
1712 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1713
1714 int ip6_tnl_get_iflink(const struct net_device *dev)
1715 {
1716         struct ip6_tnl *t = netdev_priv(dev);
1717
1718         return t->parms.link;
1719 }
1720 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1721
1722 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1723                           unsigned int num)
1724 {
1725         if (num >= MAX_IPTUN_ENCAP_OPS)
1726                 return -ERANGE;
1727
1728         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1729                         &ip6tun_encaps[num],
1730                         NULL, ops) ? 0 : -1;
1731 }
1732 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1733
1734 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1735                           unsigned int num)
1736 {
1737         int ret;
1738
1739         if (num >= MAX_IPTUN_ENCAP_OPS)
1740                 return -ERANGE;
1741
1742         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1743                        &ip6tun_encaps[num],
1744                        ops, NULL) == ops) ? 0 : -1;
1745
1746         synchronize_net();
1747
1748         return ret;
1749 }
1750 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1751
1752 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1753                         struct ip_tunnel_encap *ipencap)
1754 {
1755         int hlen;
1756
1757         memset(&t->encap, 0, sizeof(t->encap));
1758
1759         hlen = ip6_encap_hlen(ipencap);
1760         if (hlen < 0)
1761                 return hlen;
1762
1763         t->encap.type = ipencap->type;
1764         t->encap.sport = ipencap->sport;
1765         t->encap.dport = ipencap->dport;
1766         t->encap.flags = ipencap->flags;
1767
1768         t->encap_hlen = hlen;
1769         t->hlen = t->encap_hlen + t->tun_hlen;
1770
1771         return 0;
1772 }
1773 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1774
1775 static const struct net_device_ops ip6_tnl_netdev_ops = {
1776         .ndo_init       = ip6_tnl_dev_init,
1777         .ndo_uninit     = ip6_tnl_dev_uninit,
1778         .ndo_start_xmit = ip6_tnl_start_xmit,
1779         .ndo_do_ioctl   = ip6_tnl_ioctl,
1780         .ndo_change_mtu = ip6_tnl_change_mtu,
1781         .ndo_get_stats  = ip6_get_stats,
1782         .ndo_get_iflink = ip6_tnl_get_iflink,
1783 };
1784
1785 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1786                          NETIF_F_FRAGLIST |     \
1787                          NETIF_F_HIGHDMA |      \
1788                          NETIF_F_GSO_SOFTWARE | \
1789                          NETIF_F_HW_CSUM)
1790
1791 /**
1792  * ip6_tnl_dev_setup - setup virtual tunnel device
1793  *   @dev: virtual device associated with tunnel
1794  *
1795  * Description:
1796  *   Initialize function pointers and device parameters
1797  **/
1798
1799 static void ip6_tnl_dev_setup(struct net_device *dev)
1800 {
1801         dev->netdev_ops = &ip6_tnl_netdev_ops;
1802         dev->needs_free_netdev = true;
1803         dev->priv_destructor = ip6_dev_free;
1804
1805         dev->type = ARPHRD_TUNNEL6;
1806         dev->flags |= IFF_NOARP;
1807         dev->addr_len = sizeof(struct in6_addr);
1808         dev->features |= NETIF_F_LLTX;
1809         netif_keep_dst(dev);
1810
1811         dev->features           |= IPXIPX_FEATURES;
1812         dev->hw_features        |= IPXIPX_FEATURES;
1813
1814         /* This perm addr will be used as interface identifier by IPv6 */
1815         dev->addr_assign_type = NET_ADDR_RANDOM;
1816         eth_random_addr(dev->perm_addr);
1817 }
1818
1819
1820 /**
1821  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1822  *   @dev: virtual device associated with tunnel
1823  **/
1824
1825 static inline int
1826 ip6_tnl_dev_init_gen(struct net_device *dev)
1827 {
1828         struct ip6_tnl *t = netdev_priv(dev);
1829         int ret;
1830         int t_hlen;
1831
1832         t->dev = dev;
1833         t->net = dev_net(dev);
1834         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1835         if (!dev->tstats)
1836                 return -ENOMEM;
1837
1838         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1839         if (ret)
1840                 goto free_stats;
1841
1842         ret = gro_cells_init(&t->gro_cells, dev);
1843         if (ret)
1844                 goto destroy_dst;
1845
1846         t->tun_hlen = 0;
1847         t->hlen = t->encap_hlen + t->tun_hlen;
1848         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1849
1850         dev->type = ARPHRD_TUNNEL6;
1851         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1852         dev->mtu = ETH_DATA_LEN - t_hlen;
1853         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1854                 dev->mtu -= 8;
1855         dev->min_mtu = ETH_MIN_MTU;
1856         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1857
1858         return 0;
1859
1860 destroy_dst:
1861         dst_cache_destroy(&t->dst_cache);
1862 free_stats:
1863         free_percpu(dev->tstats);
1864         dev->tstats = NULL;
1865
1866         return ret;
1867 }
1868
1869 /**
1870  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1871  *   @dev: virtual device associated with tunnel
1872  **/
1873
1874 static int ip6_tnl_dev_init(struct net_device *dev)
1875 {
1876         struct ip6_tnl *t = netdev_priv(dev);
1877         int err = ip6_tnl_dev_init_gen(dev);
1878
1879         if (err)
1880                 return err;
1881         ip6_tnl_link_config(t);
1882         if (t->parms.collect_md) {
1883                 dev->features |= NETIF_F_NETNS_LOCAL;
1884                 netif_keep_dst(dev);
1885         }
1886         return 0;
1887 }
1888
1889 /**
1890  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1891  *   @dev: fallback device
1892  *
1893  * Return: 0
1894  **/
1895
1896 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1897 {
1898         struct ip6_tnl *t = netdev_priv(dev);
1899         struct net *net = dev_net(dev);
1900         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1901
1902         t->parms.proto = IPPROTO_IPV6;
1903         dev_hold(dev);
1904
1905         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1906         return 0;
1907 }
1908
1909 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1910                             struct netlink_ext_ack *extack)
1911 {
1912         u8 proto;
1913
1914         if (!data || !data[IFLA_IPTUN_PROTO])
1915                 return 0;
1916
1917         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1918         if (proto != IPPROTO_IPV6 &&
1919             proto != IPPROTO_IPIP &&
1920             proto != 0)
1921                 return -EINVAL;
1922
1923         return 0;
1924 }
1925
1926 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1927                                   struct __ip6_tnl_parm *parms)
1928 {
1929         memset(parms, 0, sizeof(*parms));
1930
1931         if (!data)
1932                 return;
1933
1934         if (data[IFLA_IPTUN_LINK])
1935                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1936
1937         if (data[IFLA_IPTUN_LOCAL])
1938                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1939
1940         if (data[IFLA_IPTUN_REMOTE])
1941                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1942
1943         if (data[IFLA_IPTUN_TTL])
1944                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1945
1946         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1947                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1948
1949         if (data[IFLA_IPTUN_FLOWINFO])
1950                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1951
1952         if (data[IFLA_IPTUN_FLAGS])
1953                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1954
1955         if (data[IFLA_IPTUN_PROTO])
1956                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1957
1958         if (data[IFLA_IPTUN_COLLECT_METADATA])
1959                 parms->collect_md = true;
1960
1961         if (data[IFLA_IPTUN_FWMARK])
1962                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1963 }
1964
1965 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1966                                         struct ip_tunnel_encap *ipencap)
1967 {
1968         bool ret = false;
1969
1970         memset(ipencap, 0, sizeof(*ipencap));
1971
1972         if (!data)
1973                 return ret;
1974
1975         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1976                 ret = true;
1977                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1978         }
1979
1980         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1981                 ret = true;
1982                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1983         }
1984
1985         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1986                 ret = true;
1987                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1988         }
1989
1990         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1991                 ret = true;
1992                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1993         }
1994
1995         return ret;
1996 }
1997
1998 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1999                            struct nlattr *tb[], struct nlattr *data[],
2000                            struct netlink_ext_ack *extack)
2001 {
2002         struct net *net = dev_net(dev);
2003         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2004         struct ip_tunnel_encap ipencap;
2005         struct ip6_tnl *nt, *t;
2006         int err;
2007
2008         nt = netdev_priv(dev);
2009
2010         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2011                 err = ip6_tnl_encap_setup(nt, &ipencap);
2012                 if (err < 0)
2013                         return err;
2014         }
2015
2016         ip6_tnl_netlink_parms(data, &nt->parms);
2017
2018         if (nt->parms.collect_md) {
2019                 if (rtnl_dereference(ip6n->collect_md_tun))
2020                         return -EEXIST;
2021         } else {
2022                 t = ip6_tnl_locate(net, &nt->parms, 0);
2023                 if (!IS_ERR(t))
2024                         return -EEXIST;
2025         }
2026
2027         err = ip6_tnl_create2(dev);
2028         if (!err && tb[IFLA_MTU])
2029                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2030
2031         return err;
2032 }
2033
2034 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2035                               struct nlattr *data[],
2036                               struct netlink_ext_ack *extack)
2037 {
2038         struct ip6_tnl *t = netdev_priv(dev);
2039         struct __ip6_tnl_parm p;
2040         struct net *net = t->net;
2041         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2042         struct ip_tunnel_encap ipencap;
2043
2044         if (dev == ip6n->fb_tnl_dev)
2045                 return -EINVAL;
2046
2047         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2048                 int err = ip6_tnl_encap_setup(t, &ipencap);
2049
2050                 if (err < 0)
2051                         return err;
2052         }
2053         ip6_tnl_netlink_parms(data, &p);
2054         if (p.collect_md)
2055                 return -EINVAL;
2056
2057         t = ip6_tnl_locate(net, &p, 0);
2058         if (!IS_ERR(t)) {
2059                 if (t->dev != dev)
2060                         return -EEXIST;
2061         } else
2062                 t = netdev_priv(dev);
2063
2064         return ip6_tnl_update(t, &p);
2065 }
2066
2067 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2068 {
2069         struct net *net = dev_net(dev);
2070         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2071
2072         if (dev != ip6n->fb_tnl_dev)
2073                 unregister_netdevice_queue(dev, head);
2074 }
2075
2076 static size_t ip6_tnl_get_size(const struct net_device *dev)
2077 {
2078         return
2079                 /* IFLA_IPTUN_LINK */
2080                 nla_total_size(4) +
2081                 /* IFLA_IPTUN_LOCAL */
2082                 nla_total_size(sizeof(struct in6_addr)) +
2083                 /* IFLA_IPTUN_REMOTE */
2084                 nla_total_size(sizeof(struct in6_addr)) +
2085                 /* IFLA_IPTUN_TTL */
2086                 nla_total_size(1) +
2087                 /* IFLA_IPTUN_ENCAP_LIMIT */
2088                 nla_total_size(1) +
2089                 /* IFLA_IPTUN_FLOWINFO */
2090                 nla_total_size(4) +
2091                 /* IFLA_IPTUN_FLAGS */
2092                 nla_total_size(4) +
2093                 /* IFLA_IPTUN_PROTO */
2094                 nla_total_size(1) +
2095                 /* IFLA_IPTUN_ENCAP_TYPE */
2096                 nla_total_size(2) +
2097                 /* IFLA_IPTUN_ENCAP_FLAGS */
2098                 nla_total_size(2) +
2099                 /* IFLA_IPTUN_ENCAP_SPORT */
2100                 nla_total_size(2) +
2101                 /* IFLA_IPTUN_ENCAP_DPORT */
2102                 nla_total_size(2) +
2103                 /* IFLA_IPTUN_COLLECT_METADATA */
2104                 nla_total_size(0) +
2105                 /* IFLA_IPTUN_FWMARK */
2106                 nla_total_size(4) +
2107                 0;
2108 }
2109
2110 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2111 {
2112         struct ip6_tnl *tunnel = netdev_priv(dev);
2113         struct __ip6_tnl_parm *parm = &tunnel->parms;
2114
2115         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2116             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2117             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2118             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2119             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2120             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2121             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2122             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2123             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2124                 goto nla_put_failure;
2125
2126         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2127             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2128             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2129             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2130                 goto nla_put_failure;
2131
2132         if (parm->collect_md)
2133                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2134                         goto nla_put_failure;
2135
2136         return 0;
2137
2138 nla_put_failure:
2139         return -EMSGSIZE;
2140 }
2141
2142 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2143 {
2144         struct ip6_tnl *tunnel = netdev_priv(dev);
2145
2146         return tunnel->net;
2147 }
2148 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2149
2150 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2151         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2152         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2153         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2154         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2155         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2156         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2157         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2158         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2159         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2160         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2161         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2162         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2163         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2164         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2165 };
2166
2167 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2168         .kind           = "ip6tnl",
2169         .maxtype        = IFLA_IPTUN_MAX,
2170         .policy         = ip6_tnl_policy,
2171         .priv_size      = sizeof(struct ip6_tnl),
2172         .setup          = ip6_tnl_dev_setup,
2173         .validate       = ip6_tnl_validate,
2174         .newlink        = ip6_tnl_newlink,
2175         .changelink     = ip6_tnl_changelink,
2176         .dellink        = ip6_tnl_dellink,
2177         .get_size       = ip6_tnl_get_size,
2178         .fill_info      = ip6_tnl_fill_info,
2179         .get_link_net   = ip6_tnl_get_link_net,
2180 };
2181
2182 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2183         .handler        = ip4ip6_rcv,
2184         .err_handler    = ip4ip6_err,
2185         .priority       =       1,
2186 };
2187
2188 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2189         .handler        = ip6ip6_rcv,
2190         .err_handler    = ip6ip6_err,
2191         .priority       =       1,
2192 };
2193
2194 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2195 {
2196         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2197         struct net_device *dev, *aux;
2198         int h;
2199         struct ip6_tnl *t;
2200
2201         for_each_netdev_safe(net, dev, aux)
2202                 if (dev->rtnl_link_ops == &ip6_link_ops)
2203                         unregister_netdevice_queue(dev, list);
2204
2205         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2206                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2207                 while (t) {
2208                         /* If dev is in the same netns, it has already
2209                          * been added to the list by the previous loop.
2210                          */
2211                         if (!net_eq(dev_net(t->dev), net))
2212                                 unregister_netdevice_queue(t->dev, list);
2213                         t = rtnl_dereference(t->next);
2214                 }
2215         }
2216 }
2217
2218 static int __net_init ip6_tnl_init_net(struct net *net)
2219 {
2220         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2221         struct ip6_tnl *t = NULL;
2222         int err;
2223
2224         ip6n->tnls[0] = ip6n->tnls_wc;
2225         ip6n->tnls[1] = ip6n->tnls_r_l;
2226
2227         if (!net_has_fallback_tunnels(net))
2228                 return 0;
2229         err = -ENOMEM;
2230         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2231                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2232
2233         if (!ip6n->fb_tnl_dev)
2234                 goto err_alloc_dev;
2235         dev_net_set(ip6n->fb_tnl_dev, net);
2236         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2237         /* FB netdevice is special: we have one, and only one per netns.
2238          * Allowing to move it to another netns is clearly unsafe.
2239          */
2240         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2241
2242         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2243         if (err < 0)
2244                 goto err_register;
2245
2246         err = register_netdev(ip6n->fb_tnl_dev);
2247         if (err < 0)
2248                 goto err_register;
2249
2250         t = netdev_priv(ip6n->fb_tnl_dev);
2251
2252         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2253         return 0;
2254
2255 err_register:
2256         free_netdev(ip6n->fb_tnl_dev);
2257 err_alloc_dev:
2258         return err;
2259 }
2260
2261 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2262 {
2263         struct net *net;
2264         LIST_HEAD(list);
2265
2266         rtnl_lock();
2267         list_for_each_entry(net, net_list, exit_list)
2268                 ip6_tnl_destroy_tunnels(net, &list);
2269         unregister_netdevice_many(&list);
2270         rtnl_unlock();
2271 }
2272
2273 static struct pernet_operations ip6_tnl_net_ops = {
2274         .init = ip6_tnl_init_net,
2275         .exit_batch = ip6_tnl_exit_batch_net,
2276         .id   = &ip6_tnl_net_id,
2277         .size = sizeof(struct ip6_tnl_net),
2278 };
2279
2280 /**
2281  * ip6_tunnel_init - register protocol and reserve needed resources
2282  *
2283  * Return: 0 on success
2284  **/
2285
2286 static int __init ip6_tunnel_init(void)
2287 {
2288         int  err;
2289
2290         if (!ipv6_mod_enabled())
2291                 return -EOPNOTSUPP;
2292
2293         err = register_pernet_device(&ip6_tnl_net_ops);
2294         if (err < 0)
2295                 goto out_pernet;
2296
2297         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2298         if (err < 0) {
2299                 pr_err("%s: can't register ip4ip6\n", __func__);
2300                 goto out_ip4ip6;
2301         }
2302
2303         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2304         if (err < 0) {
2305                 pr_err("%s: can't register ip6ip6\n", __func__);
2306                 goto out_ip6ip6;
2307         }
2308         err = rtnl_link_register(&ip6_link_ops);
2309         if (err < 0)
2310                 goto rtnl_link_failed;
2311
2312         return 0;
2313
2314 rtnl_link_failed:
2315         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2316 out_ip6ip6:
2317         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2318 out_ip4ip6:
2319         unregister_pernet_device(&ip6_tnl_net_ops);
2320 out_pernet:
2321         return err;
2322 }
2323
2324 /**
2325  * ip6_tunnel_cleanup - free resources and unregister protocol
2326  **/
2327
2328 static void __exit ip6_tunnel_cleanup(void)
2329 {
2330         rtnl_link_unregister(&ip6_link_ops);
2331         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2332                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2333
2334         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2335                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2336
2337         unregister_pernet_device(&ip6_tnl_net_ops);
2338 }
2339
2340 module_init(ip6_tunnel_init);
2341 module_exit(ip6_tunnel_cleanup);